Folding chair



Nov. 29, 1960 R. J. FRANK FOLDING CHAIR Filed Sept. 21. 1959 INVENTOR. RICHARD J. FRANK F L HA R Filed Sept. 21, 1959,53. N 541,355

9 Claims. (Cl. 155-140)" This invention relates generally to folding chairs and it relates more particularly to improved side rail construction therefor .and means for fastening the seat in the side rails. n

Collapsible or folding chairs of this general character shouldbe readily converted between collapsed and operative positions. In addition, the seat portion shouldalso be readily removable for cleaning or replacement when the chair is collapsed, and yet when in the operative position, the seat must be securely held in place.

Furthermore, these chairs must be as light as possible. in order to enhance their portability, and should contain a minimum number of parts for economical production.

The present invention has accordingly provided a col-. lapsible chair having all of the above desirable characteristics. More specifically, the invention contemplates that both the seat rails and arm rails are identical in cross section. and thereby are fabricated from the same stock material, these rails being of such cross sectional shape that they cooperate with one another insecurely clamping the flexible seatinplace, and from whichralls the seat can be easily and immediately removed when the chairis collapsed. Preferably, the rails are formed from an extruded, light-weight metal, such as aluminum, and are of generally tubular cross-section. Theconstruction of the present invention is such that ,the rails are secured together at the outer sides of thec'hair by means of a continuous hinge which results in a clean design, and a construction :in whichthe danger of pinched fingers when folding the chair is precludfid.

Another object of the invention is to provide an improved seat rail of extruded-aluminum orthe like which is economical to produce and efficient ,in performing the functions for which it was designed.

These and other objects and advantages will appear later as this disclosure progresses, reference being had to the accompanying drawings,-in which:

Figure 1 is a front view of achair inwhich the present invention has beenutilized;

Figure 2 is a side view ,of the chair shown in Figure 1;

Figure 3 is an enlarged sectional view taken along 3-4 of Figure 2; and

Figure 4 is a sectional view taken along line 4-4 in Figure 3, but on a reduced scale. a

Referring in greater detail to the drawings, the chair shown -for purposes of illustrating the present invention includes two pairs of pivotally connected cross legs 2 each pair having a jointed brace 3 that locks the legs in the expanded operative position in the conventional manner. The top ends of the legs at .eachside of the chair are connected together by a seat rail 4 to be later described in detail. The chair also has a side arm and back assembly at each side comprised of the back post 6, arm 7, spindle 8 and an arm rail 10, the latter of which will also be later described in detail. The back rest 11 is slipped over the back posts in the conventional manner to hold the arm assemblies in the upright position.

2,962,085 P te ed New. 22.1w

' '2 The legs 2 back posts 6 and spindles 8 are all preferably formed from lightweight metal tubular stockisnoh as aluminum and extend into their respective railswhere. they. are accurately positionedand rigidly secured, as will appear later. The general operation of the chair is conventional. To collapse the chair from the'position shown, it is only necessary to lift the back rest, 11 from at least one.0f its posts to permit the side arm assemblies to be swung outwardlyand downwardly, and then collapse the braces 3 ,which permits jthe legsto be scissored together.

The present invention provides a seat side rail ,4 and an arm side railvltl of such cross-sectional shape'that they can be formed from the same stock, thereby sub stantially redncing the number of manufacturing operations and parts required. At the same time, these rails are of such cross sectional shape that they cooperate with one another to form a smooth outer hinge edge of clean design and securely but detachably hold the seatlZ in position, In order to detach the seat it, is only necessary to swing the arm. assemblies to their collapsed position, and it is unnecessary to remove any hinges or otherparts.

Assho-wn best in Figure 3, each of the rails 4 and '10 are generally square in cross-section and hollow. These rails are formed as metal extrusions during which process an integrally formed outward extension or wall 14- is formed which extends as a continuation of one of the fiat sidesof the square rail. This extension terminates at its outer end in an enlarged portion 15 having a slot or opening 16 extending lengthwise. therethrough, as shown in Figure 2. Theenlarged portions of rails 4 and 10 are alternately cut away along their length to form complementary hinge sections that when assernbled provide a pianotype hinge along .the entire outer edge of the rails. This results in a smooth edge of clean design which prevents-the entry of the users fingers between the outer edges of the rails when the chair is being folded to the erect or operative position, and it furthermore encloses the .seat locking means to be .described.

The rails 4 and 10' are extruded with a projecting memberin .the form of a pair o-fribs 18 extending along the inside of the inner wall 19 and bymeans .of which the posts 6, spindles .8 and legs 2 can be accurately located and rigidly vsecured within their rails. This is accomplished by using a drill to form an aperture 2.0 in the opposite sideof the rail from these ribs, and then continuing to insert the drill sufiiciently into the interior of the rail, and atthe proper angle, so as to cut away a portion 21 onf each of the ribs to define an opening or recess into which the end of post, spindle or leg, as the case maybe, ispnngly inserted. As the aperture 20 also snugly receives its respective member, the member is rigidly held byfits .rail at two spaced locations along ,its length and Prevented from twisting relative thereto. ,The inserted member is securely held .captive in its rail by means of the bolt, 22 extending through the rail to engage its parachute washer 23 .Which has been previously located within the member.

The rails 4 and 10 also have a retaining rib 26 formed along the outsideof the inner wall 19. Thisrib is located adjacent the extension 14, which together with wall 19 forms a rectangular groove 28. When therails 4t and 10, .are in ,the operative position shown in Figure 3, the inner walls v19 .of the rails face one another and define an enclosed area 29 in which is located ,the lock ing groove28 and .the edge .of the .seatheld therein, as follows. Y

V Theedge of the seat is doubled over itselfland sewed alQ gits sides to .fo m .a loop .i t whi h heseat core or anchor bar'31 is inserted. The cross-sectional dimension and shape of the bar 31 is such that when it is inserted in the loop 30 and placed in the groove 28, the latter is substantially filled. The seat 12 extends from between the flattened and complementary corners 33 and the pulling action of the seat urges the rod tightly against the rib and tends to twist the bar in its groove. However, due to the inclined position of the rib 26, and the rail 4 in general, the bar 31 cannot be pulled from its groove but remains firmly in place regardless of the pulling force exerted due to weight on the seat. The rib 26 on the upper arm rail extends downwardly to adjacent the seat and additionally insures that the bar is held captive.

At the point where the seat passes the complementary clamping corners 33, additional layers 35 of seat material may, if desired, be sewed to the seat for purposes of generally insuring a tight assembly. The action is such as to take the looseness out of the assembly by'biasing the arm assemblies outwardly to a slight degree and thereby creating the desired degree of tautness in the back rest 11. Thus, any looseness, due primarily to play in the hinge joint is absorbed by the clamping action of the rail corners on the seat.

Thus, the rails 4 and 10 have seat retaining grooves 28 located along the outside of their oppositely facing and enclosed walls 19, and also have the reinforcing and locating member 18 formed along their inner sides. Other complementary portions of the identical rails 4 and 10 which cooperate with one another are the hinge containing extensions 14 and the seat clamping surfaces 33. i

A particularly neat appearing assembly is provided in which the seat edge and its core are completely enclosed between the rails, one of which is inclined at an angle to the other. This inclination permits a highly eflicient locking groove to be provided at the proper angle in respect to direction of force on the seat, and furthermore permits the slanting legs to extend in a normal relation to the rail wall for maximum strength.

Various modes of carrying out the invention are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention.

What is claimed and desired to be secured by Letters Patent is:

1. In a folding chair including a pair of pivotally connected legs, a seat rail rigidly connecting the legs located at each side of the chair, an arm assembly for each seat rail and including a rail and a back post, a back rest detachably connected between said back posts, said seat rails and arm assembly rails being of similar cross-sectional shape and formed as a rectangular tubular aluminum extrusion and having an integral extension extending as a continuation of one of its sides, said extensions being pivotally secured together to form a hinge between the rails at each side of the chair, whereby said assemblies are swingable in respect to their seat rails between collapsed and operative positions, said rails each having a second side facing one another when in said operative position to thereby define together with said extensions an enclosed area therebetween, an integrally formed rib extending from each of said second sides and adjacent their respective extension to define therewith a locking groove, a flexible seat extending between the rails at each side of the chair, a seat core secured to opposite sides of said seat and adapted to be received in said grooves, said rails when in the operative position being adapted to embrace said seat therebetween at a location spaced from said extensions whereby said core and locking groove are located in said enclosed area.

2. In a folding chair including a pair of pivotally connected legs, a seat rail rigidly connecting the legs located at each side of the chair, an arm assembly for each seat rail and including a rail and a back post, a back rest detachably connected between said back posts, said seat rails and arm assembly rails each being a hollow aluminum extrusion of similar cross-sectional shape and having an integral extension along their length which extends outwardly therefrom, said extensions being pivotally secured together at their outer ends to form a hinge between the rails at each side of the chair, whereby said assemblies are swingable in respect to their seat rails between collapsed and operative positions, said rails each having an integrally formed rib along its length which together with its extension defines a locking groove, a flexible seat extending between the rails at each side of the chair, an anchor bar secured to opposite sides of said seat and adapted to be snugly received in said grooves, said rails when in the operative position being adapted to embrace said seat therebetween at a location spaced from said extension so as to define an enclosed area in which said bar and locking groove are located, and said seat rail is inclined at an angle to said assembly rail whereby the line of force due to tension on said seat acts generally normally to said rib.

3. In a folding chair including a pair of pivotally connected legs, a seat rail rigidly connected to the legs, an arm assembly for each seat rail and including a rail normally supported above said seat rail, said seat rails and arm assembly rails each having an integral extension along their length, said extensions being pivotally secured together to form a hinge between the rails whereby said assemblies are swingable in respect to their seat rails between collapsed and operative positions, said rails each having means which define a locking groove along their length and adjacent said extension, a flexible seat having an anchor bar secured along opposite sides thereof, said bars adapted to be snugly received in said grooves, said rails when in the operative position being adapted to embrace said seat therebetween at a location spaced from said extensions so as to define an enclosed area in which said bar and locking groove are located.

4. A side rail assembly for a collapsible chair comprising, a seat rail having legs extending therefrom, an arm assembly rail normally located above the said seat rail and supported thereby, said rails being similar in cross-sectional shape and comprising a generally square aluminum tube, an extension formed integrally along the length of said tube, hinge elements formed along the free edge of said extensions for mounting said rails together for swinging to an operative position to define an enclosed area therebetween which is defined in part by one side of each rail, and means on said one side of said rails and forming a locking groove therealong.

5. A side rail assembly for a collapsible chair comprising, a seat rail having legs extending therefrom, an arm assembly rail normally located above the said seat rail and supported thereby, said rails being similar in cross-sectional shape and comprising a generally square aluminum tube, an extension formed integrally along said tube as a continuation of one of its sides, a hinge element formed on the free edge of said extension whereby said rails are hingeable together for swinging between operative and collapsed positions, said rails each having a second side facing one another when in said operative position so as to define together with said extensions an enclosed area therebetween, and a rib extending along said second side and adjacent said extension to form a groove therewith, said seat rail and its legs being inclined at an angle to said arm assembly rail when in the operative position to thereby enclose said grooves between said rails.

6. A folding chair including a pair of pivotally connected legs, a seat rail rigidly connected to the legs at each of two opposite sides of the chair, an arm rail for each seat rail and including arm supports extending therefrom and normally supported above said seat rail, said rails being formed of hollow aluminum extrusions and having hinge elements along their length whereby they are pivotally secured together and are swingable to an operative position to define an enclosed area therebetween which is defined in part by one side of each rail, said rails each having means which define a locking groove along their said one side and within said enclosed area, a rein-forcing member formed within said hollow rails and on said one side thereof, said member having a locating recess for securely positioning said legs and arm supports therein, and a flexible seat having an anchor bar secured along opposite sides thereof, said bars adapted to be received in their corresponding locking groove, said rails when in the operative position being adapted to embrace said seat therebetween at a location spaced from said hinge.

7. A side rail assembly for a collapsible chair comprising, a seat rail having legs extending therefrom, an arm assembly rail normally located above the said seat rail and supported thereby, said rails comprising a tubular extrusion having a hinge element formed integrally along their length for mounting said rails together for swinging to an operative position to define an enclosed area therebetween which is defined in part by a portion of each rail, and means on said portion of said rails and forming a locking groove therealong.

8. In a collapsible chair, a seat rail having legs extending therefrom, an arm assembly including a rail and arm supports and normally located above the said seat rail and supported thereby, said rails being similar in cross-sectional shape and comprising a tubular extrusion having an extension formed integrally along their length, hinge elements formed along said extension for mounting said rails together for relative swinging to an operative position to define an enclosed area therebetween which is defined in part by a portion of each rail, means on said portion of said rails and forming a locking groove therealong,

and means formed within said tubular rails for locating" and securely positioning their respective legs and arms.

9. As an article of manufacture, a collapsible seat rail comprising an extruded aluminum tube of generally square cross section and having an extension formed integrally along its length and as a continuation of one of its sides so as to extend beyond a second tube side, a rib formed integrally along said second side and adjacent said extension so as to form a seat core retaining groove therewith, and a reinforcing and leg locating projection formed within the tube on said second side, said projection having a leg receiving recess, said tube having an aperture on its side opposite said second side and through which a leg is adapted to pass for insertion in said recess.

References Cited in the file of this patent UNITED STATES PATENTS 34,204 Goodwin Jan. 21, 1862 1,703,879 Goldwin Mar. 5, 1929 1,858,254 Uline May 17, 1932 2,284,074 Stahl May 26, 1942 2,288,013 Moynahan et al June 30, 1942 2,517,039 Shook Aug. 1, 1950 2,582,864 Gittings et al I an. 15, 1952 2,627,327 Backman Feb. 3, 1953 2,629,432 Hanslick Feb. 24, 1953 2,800,171 Hoven et al July 23, 1957 2,839,126 ONeill June 17, 1958 2,914,111 Mize Nov. 24, 1959 2,922,170 Reggiani Jan. 26, 1960 

